1. Field of the Invention
The present invention relates to an apparatus for inhibiting foreign material from being deposited on the rear window of a motorcar and more particularly to an apparatus for inhibiting foreign material such as mud, dust or the like on the rear window of a motorcar by allowing air flowing along the upper surface of the car body during movement of the motorcar to be introduced toward the rear window frame to flow along the upper surface of the latter and moreover effectively cleaning the rear windshield.
2. Description of the Prior Art
As is well known, when a motorcar runs on road or ground in the rain or it travels on muddy road even in fine weather, foreign material such as mud sprashed up by rear wheels, dust or the like tends to be deposited on the rear window. Thus deposited foreign material causes a driver to observe rear sight through the rear windshield with much difficulties and moreover it degrades the car appearance.
To obviate the foregoing problem there was proposed mounting of an air flow control plate on the rear part of the upper surface of a car body as disclosed in Japanese Utility Model Laid-Open No. 40266/73. The conventional air flow control plate is intended to introduce air flowing along the body roof toward the rear window therethrough so as to allow it to flow further along the upper surface of that window for the purpose of inhibiting foreign material such as mud, dust or the like from being deposited on the rear windshield.
However, it is pointed out as a drawback inherent to the conventional air flow control plate that since the air flow control plate is projected upwardly of the body roof, there occurs increase in projected area as seen from the front side, resulting in increased air resistance during travelling of a motorcar.
On the other hand, to clean a windshield fitted to the rear window a windshield cleaning apparatus is already proposed which has a cleaning nozzle fixedly disposed at the rear upper part of the car body to spray cleaning liquid toward the upper surface of the rear windshield from the nozzle to clean it. In such conventional cleaning apparatus, if the amount of upward projection of the cleaning nozzle from the upper surface of the car body is restricted to a minimum extent in view of the external appearance of a motorcar, it in turn results disadvantageously in that the nozzle is forced to have a very small spraying angle relative to the upper surface of a rear windshield to be cleaned. Accordingly, there is necessity for determining a spraying angle of the nozzle with very high accuracy in order to enable cleaning liquid to be sprayed over the upper surface of the windshield without fail. This leads to an increased production cost. Another drawback of the conventional windshield cleaning apparatus is that any minor projection of the cleaning nozzle upwardly of the upper surface of the car body degrades appearance of the whole car.
It should be noted that arrangement of the cleaning apparatus at the upper rear part of the car body inevitably raises problems of how and where to mount components other than cleaning nozzle on the body.